Grinding-rolls for treating wheat and other granular substances.



F. STACEY.

GRINDING ROLLS FOB. TING WHEAT AND OTHE ANULAR SUBSTANCES.

LIOATION FILED JAN. 26, l

1,055,096. Patented Mar. 4, 1913.

FRANK STACEY, or BIRMINGHAM, ENGLAND.

GRINDING-ROLLS FOR TREATING WHEATAND OTHER GRANULAR SUBSTANCES.

Specification a Letters Patent.

Application filed January 26, 1911. Serial No. 604,883.

Patented Mar. 4, 1913.

To all whom it may concern:

are either straight'ones Be it known that I, FRANK STACEY, a subject of the King of Great Britain, residing at Vauxhall street, in the cit-y of Birmingham; county of Warwick, England, have invented certain new and useful Improvements in Grinding-Rolls for Treating Wheat and other Granular Substances, of which the following is a specification.

In millingwheat it is generally the practice when dealing with pure break meal comprising the grades known as semolina middlings, and dunstl to grind or reduce the same by plain or smooth surfaced chilled iron rolls and owing to the flaking tendency of such rolls auxiliary machines called 'detachers are largely used to break up the flaked stock and such rubbing action is apt to discolor or lower the color of the flour to some extent. It is to the grinding or reducing of such pure or nearly pure stock that my invention relates and the invention consists in the use of chilled rolls whose grinding surfaces are very finely corrugated, cut,or grooved in the substantial proportions of at least eighty cuts or grooves to the circumferential inch, and in some cases as many as one hundred cuts or grooves or even more to said inch. The said grooves or cuts which form saw toothed or other shaped cross sectional rises, longitudinally of the roll surface or right or ,left hand long pitched helicalones, or of wave formation directed either axially or obliquely, and are formed throughout the full extent of the grinding surface.v

The smooth-surfaced rolls employed for the reduction of the break meal exert a crushing action upon the crystal-like particles and deform many of the crystals or groups of crystals into flat disks or flakes which are incorporated in the ultimate product and lower the quality thereof. Some of these flakes are too large to pass through the silk of the separating or dress- 1n tailings or offal. In this way there is quite an appreciable .loss in the yield. The rolls exert considerable pressure upon the stock and the resultant friction not only increases the load on the motor but causes the rolls to become somewhat highly heated. Owing to this heat, the rolls take up moisture from the stock and thus cause a further loss in. the yield. This liberation of moisture is also machines and.ultimately go off with the disadvantageous in that condensation takes place upon the walls of the casing in which the rolls are mounted and some of the con-.

densed moisture, mixing with the stock as it passes to the separating or dressing machine, causes pasty or lumpy formations which choke or clog the silk of such machine and thus lower the effectiveness of its action.

The reducingrolls which form the subject of the present invention effect the reduction of the break meal into flour, not by a crushing action, as is the case with the smooth-surfaced rolls, but by a cutting action purely, in which the crystals are pro.- gresslvely divided'into smaller crystals of like character,but in which there is no def mation of the crystals into flakes. The diliciency of the action depends upon the sharpness of the corrugations, and the rolls are definitely spaced to prevent contact of the sharp cutting edges when there is no feed on the mill. It follows that the friction which is incident to the action of the smoothsurfaced rolls is eliminated and, as a conseuence,.the rolls frun cool, and the load on t e motor is reduced. While the fine corrugations of the rolls effectively cut the crystals of,the break meal, they do not cut the germ or any branny matter which may still remainin the meal, but merely crinkle these extraneous particles and thereby provide for their ready separation with the tailings by the dressin machines.

The flour obtained rom the corrugated reducing rolls which form the subject of the present invention is of alively or bright character, and is of the highest quality. There is also a substantial increase in the the smooth-surfaced rolls. Inasmuch as the flaking tendency of the" smooth-surfaced rolls is avoided, there is no occasion for the use of detachers. 1

The drawings forming part hereof diagrammatically illustrate roll surfaces according to the invention, it being however clearly understood that the invention is not, per se, a chilled roll whose surface is corrugated, cut or grooved, but only such having grooves or cuts approximating from 80 to 100 or more per circumferential inch for use for the purpose of grinding or reducing pure or substantially pure break meal stock.

Figure 1 is a longitudinal elevation of a chilled roll whose grinding surface is long- .yield over the yield which is obtained by pitched helically cut or grooved, a number only of the grooves andconsequent teeth being diagrammatically illustrated. Fig. 2 is a similar elevation where the cuts or grooves and consequent teeth are straight ones parallel with the axis of the roll. 4 Fig. 3 is an enlarged cross section of a portion of a roll showingata, the grooves and conse quent ridges or teethwhich are substantially of saw toothed section, this formation being common to all the forms represented.

Inall the formations of grooves and consequent ridges or teeth the proportion is from about 80 to 100 or more cuts or grooves per circumferential inch, that is to say'per circumferential inch looked at from the end of the roll. It will be" clearly understood that the proportions of cuts to the inch given are somewhat dependable upon the character of the stock treated. There is in the case of the lesser number a proportion below which the rolled" surface would cease to have the advantageous effects on the stock desired and set out, and at the same time in the case of the larger number to the inch a proportion when the formation of the cuts the 1 gra n and and the consequent teeth wouldfbe impracthe proportions given are those I claim and desire to secure by Letters Patentis':- e Y Achilled roll for reducing pure or substantially pure break meal stock having its periphery longitudinally corrugated throughout its extent, the corrugations .be-

ing formed to provide relatively sharp vc'utting' edges formed to crinkle the germ of to act with a purely cutting action on the main stock to form crystallike particles, mately eighty to dred to the inch. x

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses. I

- FRANK STACEY,

the inch to about one hun- Witnesses GEO. FUERY, DORA LEAKER.

and ranging from approxl- 

